Before the First World War India imported British steel for rails. When in 1914 the war broke out, steel produced in Britain now had to meet the demands of the war in Europe. So, imports of British steel into India declined and the Indian Railways turned to TISCO for the supply of rails.

As the war dragged on for several years, TISCO had to produce shells and carriage wheels for the war. By 1919 the colonial government was buying 90% of the steel manufactured by TISCO. Over time TISCO became the biggest steel industry within the British empire.